Deetherification process

ABSTRACT

Ethers such as isobutyl tertiary butyl ether are dissociated into their component alcohols and isolefins by heat stabilized catalyst compositions prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

This invention was made with Government support under Contract No.DE-FC07-80CS40454 awarded by the Department of Energy. The Governmenthas certain rights in this invention.

This application is a continuation in part of Ser. No. 517,220 filedJuly 25, 1983.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to acid cation exchange resins which havebeen modified to form substantially neutral metal salts thereof, whichhave been found to be superior catalysts for several processes.

2. Related Art

The acid cation exchange resins are well known and have a wide varietyof uses. The resins are cation exchangers, which contain sulfonic acidgroups, and which may be obtained by polymerization or copolymerizationof aromatic vinyl compounds followed by sulfonation. Examples ofaromatic vinyl compounds suitable for preparing polymers or copolymersare: styrene, vinyl toluene, vinyl naphthalene, vinyl ethylbenzene,methyl styrene, vinyl chlorobenzene and vinyl xylene. A large variety ofmethods may be used for preparing these polymers; for example,polymerization alone or in admixture with other monovinyl compounds, orby crosslinking with polyvinyl compounds; for example, with divinylbenzene, divinyl toluene, divinylphenylether and others. The polymersmay be prepared in the presence or absence of solvents or dispersingagents, and various polymerization initiators may be used, e.g.,inorganic or organic peroxides, persulfates, etc.

The sulfonic acid group may be introduced into these vinyl aromaticpolymers by various known methods; for example, by sulfating thepolymers with concentrated sulfuric and chlorosulfonic acid, or bycopolymerizing aromatic compounds which contain sulfonic acid groups(see e.g., U.S. Pat. No. 2,366,007). Further sulfonic acid groups may beintroduced into the polymers which already contain sulfonic acid groups;for example, by treatment with fuming sulfuric acid, i.e., sulfuric acidwhich contains sulfur trioxide. The treatment with fuming sulfuric acidis preferably carried out at 0 to 150 degrees C. and the sulfuric acidshould contain sufficient sulfur trioxide so that it still contains 10to 50% free sulfur trioxide after the reaction. The resulting productspreferably contain an average of 1.3 to 1.8 sulfonic acid groups peraromatic nucleus. Particularly, suitable polymers which contain sulfonicacid groups are copolymers of aromatic monovinyl compounds with aromaticpolyvinyl compounds, particularly, divinyl compounds, in which thepolyvinyl benzene content is preferably 1 to 20% by weight of thecopolymer (see, for example, German Patent Specification No. 908,247).

The ion exchange resin is generally used in a granular size of about0.25 to 1 mm, although particles from 0.15 mm up to about 2 mm may beemployed. The finer catalysts provide high surface area, but also resultin high pressure drops through the reactor. The macroreticular form ofthese catalysts have much larger surface area exposed and limitedswelling which all of these resins undergo in a non-aqueous hydrocarbonmedium compared to the gelular catalysts.

The acid cation exchange resins have been widely used in etherificationsand have recently been found to be useful for deetherifications andtransetherifications. Other reactions known to be carried out with theaid of cation exchange resins include dimerizations, hydration ofolefins, esterifications and epoxidations.

The modified cation exchange resin catalyst of the present inventionhave been found particularly useful for deetherifications, dehydrationand hydration of organic compounds.

The modified catalysts of the present invention exhibit substantialimprovement in thermal stability compared to the base resin, however,the catalysts continue to exhibit the properties of acid catalysts.Furthermore, the present catalysts have been observed to be moreselective in reactions.

The simplicity and safety of the present process which produces thepresent high temperature, active resin type catalysts is an advantageover other types of stabilizations wherein the resins are chlorinated orbrominated.

SUMMARY OF THE INVENTION

In its broader aspects the present invention relates to improvedcatalysts compositions which are nuclear sulfonic acid solid resinswhich have at least 50% of the sulfonic acid groups neutralized withmetal ions of Group 4b, 5b, 6b, 7b, 8, 1b or 2b, and of the PeriodicTable of elements, the rare earth metals or mixtures thereof, and thebalance of the sulfonic acid groups neutralized with an alkali metal oralkaline earth metal, ammonium or mixtures thereof. The sulfonic acidmay be attached to any polymeric backbone. The preferred metals are Ti,V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Ta, W,Re, Pl, Ce, Nd, Sm, and Eu.

The present invention includes the method of preparing cation resincatalysts, cation resin catalysts, and the processes using thecatalysts.

In a preferred embodiment the present catalyst is prepared by contactinga macroporous matrix containing a sulfonic acid group with aqueoussolution of metal salts and solutions of alkali metal salts, alkalineearth metal salts and/or ammonium salts to neutralize the acid groups.Alkali metal and alkaline earth metal ions are preferred for theneutralization.

In a preferred procedure the present catalysts are prepared bycontacting a sulfonic acid cation exchange resin comprising amacroporous matrix of a polyvinyl aromatic compound crosslinked with adivinyl compound and having thereon from about 3 to 5 milli equivalentsof sulfonic acid groups per gram of dry resin (1) with an aqueoussolution of a soluble compound of an alkali metal or alkaline earthmetal of Group 1a or 2a of the Periodic Table of elements or mixturesthereof in an amount to neutralize all of the available sulfonic acidgroups and (2) thereafter contacting said neutralized resin with anaqueous solution of a soluble salt of a metal as described andpreferably a soluble salt of Al, Fe, Zn, Cu, Ni or mixtures thereof toreplace at least 50% of the alkali metal, alkali earth metal or mixturesthereof associated with said sulfonic acid groups with said metal.

In an alternate procedure the present cation resin catalyst compositionis prepared by contacting, a sulfonic acid cation exchange resincomprising a macroporous matrix of a polyvinyl aromatic compoundcrosslinked with a divinyl compound and having thereon from about 3 to 5milli equivalents of sulfonic acid groups per gram of dry resin, (1)with an aqueous solution of a soluble metal salt as described andpreferably of Al, Fe, Zn, Cu, Ni or mixtures thereof to neutralize atleast 50% to less than 100% of the available sulfonic acid groups withsaid metal ions to produce a partially neutralized resin and (2)thereafter contacting said partially neutralized resin with an aqueoussolution containing a soluble compound of an alkali or alkaline earthmetal of Group 1a or 2a, of the Periodic Table of elements or mixturethereof to neutralize the remaining sulfonic acid groups.

Following either procedure substantially equivalent catalysts which arefully neutralized are obtained.

The resin catalyst composition is a solid comprising a macroporousmatrix of polyvinyl aromatic compound crosslinked with a divinylcompound and having thereon from about 3 to 5 milli equivalents ofsulfonic acid groups per gram of dry resin, wherein at least 50% to lessthan 100% preferably at least 59% and more preferably 70 to 90% of saidsulfonic acid groups are neutralized with a metal ion as described andpreferably Al, Fe, Zn, Cu, Ni or mixtures thereof and said sulfonic acidgroups not neutralized with said metal ion are neutralized preferablywith alkali or alkaline earth metal ions of Group 1a or 2a of thePeriodic Table of elements, ammonium ions or mixtures thereof.

The modified acidic cation exchange resins, i.e., the neutralized resinsof the present invention have been found to be stable at fairly hightemperatures (for resin type catalysts), e.g., temperatures of 150°-200°C. may be used for operations with good time trend for catalyst activityand structural integrity. The catalyst are suitable for both liquidphase and vapor phase (or mixed phase) organic reactions.

The catalysts are preferably employed in a fixed bed, in any of theconventional configurations, such as tubular reactors, packed in asingle continuous bed or in supported structures as described in U.S.Pat. Nos. 4,250,052; 4,215,011 and 4,302,356.

The catalyst may be used in processes by passing the reactants in vaporphase or liquid phase (as indicated by equilibrium considerations)through the fixed bed. Similarly, the catalyst in supported structuresas described in U.S. Pat. Nos. 4,250,052; 4,215,011 and 4,302,356 may beused as both a catalyst contact and distillation structure where thereaction products are conveniently concurrently made and separated bydistillation.

The deetherification to produce an olefin and an alcohol is mostconveniently carried out in a fixed bed with the feed in vapor phase attemperature in the range of 150° C-190° C. preferably below 180° C.,i.e., about 160° C. to 170° C., at LHSV (liquid hourly space velocity)preferably of about 1 to 10 and more preferably about 3 to 6. The etherswhich may be easily dissociated are those of the general formula

    R.sub.1 --O--R.sub.2

wherein R₁ is a hydrocarbon radical having 4 or 5 carbon atoms and R₂ isa hydrocarbon radical having 1 to 6 carbon atoms. The hydrocarbonradicals may be straight chain or branches. Some illustrative ethers aremethyl tertiary butyl ether, ethyl tertiary butyl ether, propyl tertiarybutyl ether, butyl tertiary butyl ether, tertiary butyl tertiary butylether, pentyl tertiary butyl ether, hexyl tertiary butyl ether, methyl2-methyl butyl ether, methyl 3-methyl butyl ether, ethyl n-amyl ether,methyl isoamyl ether and the like.

The dissociation of the ethers is favored at higher temperatures, thatis, the equilibrium constant shifts toward dissociation at the highertemperatures recited. It is an advantage that the higher temperatureallow higher pressures of 4 to 40 atmospheres, preferably about 5 to 10atmospheres of operation in the vapor phase and the hydrocarbon, i.e.,C₄ or C₅ olefin, dissociation product can be condensed at the higherpressure without refrigeration, i.e., condensation water at ambienttemperatures can be used.

The use of the present catalyst rather than conventional acidic cationexchange resins for deetherification is advantageous since the reactionis more selective to the production of the olefin at high conversions.In addition, the present catalysts substantially eliminate the formationof ether by-products and acetals.

Dehydration of alcohols such as tertiary butyl alcohol can also becarried out at high temperatures and pressure in vapor phase, e.g., 130°C.-150° C. at LHSV in the range 1 to 10 using the present catalyst in afixed bed usually with pressure drops through the bed of about 1 to 30psig, preferably about 5 to 15 psig.

Hydration of unsaturated hydrocarbons such as tertiary butene to formalcohols is preferably carried out in liquid phase at temperatures inthe range of 100° C. to 130° C. at LHSV in the range of 1 to 10 usingthe present catalyst in a fixed bed with sufficient pressure to maintainthe liquid phase.

DETAILED DESCRIPTION OF THE INVENTION

Any of the acidic cation exchange resins known to the art and describedabove, preferably the macroporous form may be employed in the presentmodification procedure, however, polystyrene crosslinked with divinylbenzene is preferred. The macroporous resins are frequently referred toas macroreticular. This type of resin structure has been described inthe art since the early 1960's, for example, by K. A. Kun, and R. Kunin,"J. Poly Sci", A-1 Vol 6, page 264 (1968) and R. Kunin, E. Meitzner, N.Bortnick, "J. Am. Chem. Soc.", Vol. 84, page 305 (1962) and U.S. Pat.No. 3,037,052 to Bortnick.

The macroporous resins have heterogenous structures, and consist ofagglomerates of very small gelular microspheres. Each microsphere has amicroporous matrix structure identical to that of common gelular resinsbut much smaller than the gelular resin beads. Thus, the macroporousresins are formed of areas of microporous gel matrix interspersed withmacropores. A common example of this material is Rohm and Haas Amberlyst15. Those macroreticular sulfonic acid cation exchange resins having aspecific pore volume of at least about 0.01 cc./gm. and preferably inexcess of 0.03 cc./gm. are suitable for the present invention.

These matrixes (matrices) are sulfonated as described earlier in orderto introduce sulfonic acid groups (-SO₃ H) into the matrix to formstrongly acidic catalysts. It should be noted that anion forms of theresins are also known and prepared by the introduction of amine groupsinto the matrix. Hence, generally acidic or basic catalyst are known andused.

The catalysts of the present invention are substantially neutral(although all of the sulfonic acid sites are neutralized, on hydrolysisthe present catalyst will exhibit a slightly acidic pH) having beenneutralized with specific metal ions and preferably alkali and/oralkaline earth metal ions to obtain specific catalytic properties.

As described earlier a nuclear sulfonic acid resin, for example,macroreticular resin catalyst, preferably polyvinyl styrene crosslinkedwith divinyl benzene and sulfonated to contain from 3 to 5 milliequivalents of sulfonic acid is contacted with a solution of a watersoluble salts, as described and in a one embodiment, a salt of Al, Fe,Zn, Cu, Ni or mixtures thereof and a salt of an alkali or alkaline earthmetal. Soluble salts of the metals described are known, but someexamples are aluminum chloride, iron (Fe+3) chloride, nickel chloride,copper (Cu⁺²) chloride, zinc chloride, copper (Cu⁺²) sulfate, iron(Fe⁺³) sulfate, zinc sulfate, and the like. The mixtures of metal ionsmay include any two or more of the metals disclosed.

Preferred alkali and alkaline earth metals are Li, Na, K, Mg, Ca, Sr,Ba, or mixtures thereof. The mixtures of alkali metal ions or alkalineearth metal ions may comprise any two or more of the elements fromPeriodic Table group 1a and 2a. Suitable soluble salts include sodiumchloride, potassium chloride, lithium sulfide, magnesium acetate,calcium bromide, strontium bromide, barium bromide and the like.Ammonium chloride, for example, is illustrative of the soluble saltssuitable for use in the present process Preferred Procedure

The preferred method of catalyst preparation is advantageous since it isthe metal ion which is the active species and it is simpler to replacethe alkali or alkaline ion (or ammonium ion) to the desired extent thanavoid removing the metal ion in the alternate procedure. Theneutralization of the sulfonic acid sites with the alkali or alkalineearth metal salt solution (or ammonium salt) can be easily and quicklycarried out using a brine, e.g., NaCl in a saturated solution.

The displacement of alkali, alkaline earth or ammonium ions with themetal ion may be controlled by using the metal salt solution in portionscontaining metal ion in theoretical amounts to displace the alkali,alkaline or ammonium ions in stages or in a single solution of atheoretical amount. Analysis of a portion of the catalyst can readilydetermine if the desired displacement has taken place and if not,further treatment and analysis can be carried to arrive at the desiredlevel of metal ion concentration in the catalyst.

Of course, a continuous stream contact of a specific concentration ofthe metal salt can be plotted for specific rates, temperature, and thelike and an accurate and reproduced synthesis established.

The solutions are normally at ambient room temperature and atmosphericpressure, although temperatures in the range of 10° C. to 80° C., aresuitable and both suband super atmosphere pressure could be used forboth procedures.

As a final step in both disclosed processes the catalyst is preferablywashed with a water substantially free of electrolytes, i.e., deionizedwater or distilled water, to remove any residual contact solution. Thecatalyst may be dried in air or in various known driers or washed withmethanol then heated. In some utilizations the catalyst may be loaded inthe reactor wet and dried as part of the start up process.

Alternate Procedure

The amount of soluble metal salt present is that amount which will reactwith (neutralize) at least 50% of the active sulfonic acid sites presentin the resin being contacted and preferably an excess of salt ispresent. In no event will there be a 100% neutralization of the sulfonicactive sites with metal ions even if an excess of the salt beyond 100%is present, since these salts form acidic solutions, and an equilibriumis established, depending on the acidity, between the hydrogen ion onthe sulfonic acid group and the metal ion. It can be expected that oneFe⁺³ ion will neutralize three sulfonic acid sites as will the aluminumion, whereas metals of +2 valence will neutralize two sites per ion.

Hence, after the contact with the metal salt solution, there will stillbe some active sulfonic acid sites. These residual sulfonic acid sitesare neutralized by contacting the resin with a solution of an alkali oralkaline earth metal salt or ammonium salt. These solutions willneutralize the residual sulfonic acid sites, such that the final resinproduct is a fully neutralized material, or in practice very weaklyacidic.

In the final alkali neutralization step under the alternate procedure,care must be exercised not to contact the partially neutralized resinwith a large excess of alkali or alkaline earth metal ions, (a slightexcess up to about 20% may be used, beyond that required to neutralizethe residual sulfonic acid groups) since they appear to form doublesalts or possibly elute the metal ions, which may reduce the catalyticactivity of the catalyst. An empirical technique of the manner toproduce highly active fully neutralized resins is the use of ordinarytap water which is slightly alkaline, e.g. pH 8, which normally containsdissolved alkali and alkaline earth salts. Generally an amount overabout 10 ml of such tap water per ml of partially neutralized catalystwould be excessive.

The minimum amount of the alkali, alkaline earth or ammonium salt isdependent on the extent of neutralization in the first step. Forexample, a salt solution of copper sulfate has a high pH (3.5) andobtained a high degree of copper ion exchange, hence only 3 ml of tapwater wash per ml of resin produced an excellent catalyst, whereas 10 mlof tap water wash per ml of resin would be excessive for this catalyst.For an iron sulfate solution, pH 1, the ion exchange equilibrium islower and a 10 ml tap water wash is reasonable.

Because different metal salts (first stage neutralization) havedifferent pH's and the ion exchange equilibrium is affected by pH, someexperimentation will be desirable, initially with the amount of alkali,alkaline earth or ammonium salt solution to determine acceptable washamounts. However, once having determined equilibrium constants for eachsolution, the amount necessary can be calculated such that an excess maybe readily avoided.

It should also be appreciated that the catalytic activity varies for thedifferent metal ions and the activity of one metal ion modifier in oneprocess may not be similar when the catalyst is used in a differentprocess. In regard to deetherification, it has been observed that theactivity of the catalyst increases Ni<Zn<Cu<Fe and Al.

The modification of the acidic cation exchange resins according to thepresent invention as noted above, substantially changes thecharacteristic of the resins, namely, the high temperature propertiesare substantially improved and the activity of the catalyst is changed.One particular benefit of the change of activity in regard todeetherification is the greater selectivity of the deetherified productto the olefin corresponding to the ether, for example, deetherificationof methyl tertiary butyl ether using an unmodified resin produces smallbut detectable amounts of isobutane, dimethyl ether and acetal, whereasthe modified catalysts substantially reduce these side reactions.

The deetherifcation process using the present catalyst is carried out invapor phase, since the dissociation is favored by higher temperaturesand vapor phase (less molecular contact for the reverse reaction).

Temperatures up to about 200° C. may be used, but temperatures up to160° C. to 170° C. are preferred. Pressure may range from atmospheric upto the pressure at which the reactants and products are reduced to theliquid phase. Generally, as a desirable expedient the system is operatedat a pressure at which the desired olefin product is condensed with theleast cooling, e.g., in MTBE dissociation, isobutene can be condensedwith available ambient temperature cooling water at 70-100 psig,preferably 80-90 psig.

The etherification reaction is known to be reversible. The reaction isreversible (deetherification or dissociation) in the liquid phase, mixedliquid and vapor phase (the catalytic distillation) and in vapor phase;however, it has been observed that the dissociation equilibriumconcentrations appear to be about three times more favorable towardsproducing isobutene (or isoamylene) in the vapor phase as compared to aliquid phase system.

The present dissociation is preferably carried out in vapor phase, at atemperature which will maintain the reactants in the vapor phase. Thedissociation is endothermic.

The preparation of the ether from isobutene or isoamylene and itssubsequent dissociation according to the present process is notredundant as it may at first appear. Isobutene is a component of C₄refinery streams. The separation of the isobutene from such streams in apure state by fractionation, because of the closeness of the componentboiling points, is extremely difficult even more so if extremely highpurity isobutene is desired. However, the isobutene is readily andselectively reacted with C₁ -C₆ alcohols to form the ethers which can beseparated from the other C₄ components by conventional distillation.Thus, when the ethers are dissociated according to the present inventionextremely high purity isobutene is produced, that is isobutene with verylittle of any other C₄ present. The same considerations apply to theisoamylene.

The alkyl tertiary butyl ether or alkyl tertiary amyl ether, preferablyC₁ to C₆ alkyl tertiary butyl ether or C₁ to C₆ alkyl tertiary amylether, may be produced by any of the methods known in the art and shoulditself be a relatively pure feed to the present dissociation, quiteobviously, preferably at least 97 wt % ether and more preferably atleast about 99 wt % ether.

The neutralized cation exchange resin is preferably employed in a fixedbed. A fluidized or moving bed would operate; however, the attrition ofthe catalyst particles would render such a system unrealistic and at theleast undesirable. A catalyst packing system and catalyst structures asdescribed in U.S. Pat. No. 4,215,011 may be used in the presentdissociation and provides a convenient means of handling the catalystpacking. However, in the strictly vapor phase system, since thedissociation is in the vapor phase and not in a distillation mode, theopenness of these structures is not required and the resin beads packedinto a rector provide adequate open space to pass the vapor throughwithout inordinately high pressure drops.

In the vapor phase system it is convenient to pack or load the catalyst,which is usually in granular or bead form, into a heat exchanger havingmeans to introduce heat thereto in order to maintain the vapor phase anddesired temperatures. The feed to dissociation reactor is preferably adown flow, so as not to fluidize the catalyst bed which would result inattrition of the catalyst. In the event that the catalyst does becomefouled with heavy byproducts, these may be removed by washing thecatalyst with the liquid feed. The fixed bed may be located in a tubularreactor wherein tubes of 1/2 to 2 inches diameter are positioned througha shell into which a heat exchange medium, e.g., steam, may be emittedto maintain the heat of reaction.

The most readily available alkyl tertiary butyl ether is methyl tertiarybutyl ether (MTBE), which is widely used as an octane improver forgasoline; however, for the specialized purpose of the present inventionother alcohols can be produced in the processes used to etherifyisobutene or isoamylene, i.e., C₁ to C₆ alcohols can be used as taughtin commonly assigned application U.S. Pat. No. 4,336,407, which isincorporated herein in its entirety. These alternative ethers may haveother uses but the benefit that some offer to the present processjustifies their manufacture. The alcohols derived from the dissociationof the present ethers are monohydric, e.g., methanol, ethanol,isopropanol, tertiary butanol, isobutanol and the like.

The C₃ and higher alcohols produced by dissociation of 3-6 carbon atomalkyl tertiary ethers do not azeotrope with isobutene or isoamylene. Forexample, by using normal propyl tertiary butyl ether in the process, thealcohol dissociation product, N-propyl alcohol does not form anazeotrope with isobutene dissociation product and is easily separatedtherefrom in a fractionation.

The separation of methanol (product from MTBE) from isobutene is notdifficult and may be readily obtained by water washing of thedissociation product. The wash water, however, should be further treatedfor recycle and the methanol recovered, if the process is to beeconomically operated.

The temperature in the dissociation reactor is at or above thevaporization temperature of the ether (e.g., MTBE) at the pressure ofthe reactor. The pressure in the reactor can be subatmospheric up to apressure where the boiling point of the ether is up to about 200° C.,generally about 10 to 300 psig at LHSV of 2 to 10. The temperature inthe dissociation reactor is determined by the desired rate ofdissociation of the ether, (i.e., higher temperature favorsdissociation) and by the decomposition temperature of the catalyst. Withthese points in view the normal operating temperature is in the range of50° C. to 200° C.

The dissociation of the specified alkyl tertiary butyl ether to formisobutene and alcohol is an equilibrium reaction according to thefollowing equation: ##STR1## The rate constants K₁ and K₂ are bothtemperature dependent, however, the dissociation reaction (RTBE-K₁IB+alc.) increases much more rapidly with temperature rise than does thereverse reaction IB+alc-K₂ RTBE). The same is true for the alkyltertiary amyl ether also.

Thus, the temperatures within the ranges specified elsewhere herein arepreferred.

The hydration of olefins, particularly, tertiary olefins, such asisobutene or isoamylene is carried in liquid phase at lower temperature,e.g., around 100° C. to 130° C. and sufficient pressure to maintain theliquid phase.

The dehydration of alcohols, particularly tertiary alcohols such astertiary butanol (TBA) is carried out either in vapor phase or liquidphase (vapor phase is preferred because lower pressure may be used) attemperature of 130° C. to 150° C. Very high conversion is obtained atrelatively good space rates (LHSV 1 to 10).

The following examples will illustrate the invention but are notintended to limit the scope thereof.

EXAMPLES 1-8

In the following examples, example 1 is a control. The catalyst isordinary Amberlyst 15 purchased from Rohm and Haas. The modifiedcatalyst are the same Amberlyst 15 treated with the various saltsolutions and water as indicated. Each catalyst was dried prior to useby washing with methanol and heating. Each catalyst was placed in thesame reactor and the same feed was fed through under the sameconditions.

The reactor was a bench scale tubular reactor (3/8" OD copper tubing)containing 60 ml of the dry catalyst and heated with a steam jacket. Thecolumn was positioned vertically and a stainless steel mesh screen usedto support the catalyst bed. The feed to each run was a 50/50isobutanol/isobutyl tertiary butyl ether stream. The temperature washeld at 150° C.-160° C. for examples 2-8 and 100° C. for example 1. TheLHSV was between 3.5-5 for each run and pressure was 65-90 psig bed exitpressure.

Each of the metal salt solutions used in the first stage treatment were20% concentration. The metal salt solution was contacted with the resinat ambient room temperature (about 25° C.). After the contact with themetal salt each sample was washed with deionized water then as indicatedin TABLE I the sample was washed with tap water and in some cases withdeionized water. A final pH, which is the pH of the final wash waterthrough the catalyst is reported. This pH reflects the pH of themodified resin at the time.

In TABLE I the treatment steps and solutions are set out followed by theresults of the deetherification run. TABLE II is a typical analysis ofthe tap water used to neutralize the remaining sulfonic acid groups.

EXAMPLE 9

The catalyst of example 6 was used for a dehydration of tertiary butylalcohol at 140° C., LHSV 3. The conversion of TBA to isobutene was 90mole %.

EXAMPLE 10

Using the same catalyst as example 9, the temperature was lowered to125° C. and water and isobutene fed through the catalyst bed in liquidphase (325 psig) at LHSV 3. The isobutene comprised 15% of a C₄ stream.Five % of isobutene was converted to TBA.

EXAMPLE 11

Using the same catalyst and reactor as example 4 methanol was dehydratedto produce dimethyl ether. The reactor was heated with high pressursteam (43 lbs. pressure) through the jacket. The conditions and resultsare reported in TABLE III.

EXAMPLE 12

A catalyst was prepared by contacting macroreticular sulfonated resin(Amberlyst 15) with a 20% solution of NaCl until the acid sites wereneutralized by washing three volumes of resin three times with twovolumes of the 20% NaCl each time (total six volumes of NaCl). Followingthis the resin was washed twice with one-half volume deionized water.The neutralized catalyst was then washed three times with two volumes ofa 20% solution of zinc sulfate (total six volumes). Following this theresin was washed twice with one-half volume of deionized water. Analysisof the final catalyst showed 7.6 wt. % Zn and 2.6 wt % Na.

Sixty ml. of this catalyst was dried with methanol and placed in thereactor described in the prior examples. A feed of 99.9+% MTBE waspassed (downflow) through the catalyst with a jacket temperature of 371°F. (160 pound steam) at LHSV of 3-4. Average conversion of MTBE was 91.6wt. %. The selectivity to isobutene was 99.9 wt % and selectivity tomethanol was 99.7 wt % (GC). The MTBE was fed as a liquid to the reactorand vaporized in the reactor. The back pressure on the reactor was 80psig.

                                      TABLE I                                     __________________________________________________________________________    EXAMPLE      1   2** 3     4***                                                                              5   6   7   8                                  __________________________________________________________________________    Modification                                                                  Metal Salt   None                                                                              FeC12                                                                             Fe2(SO4)3                                                                           FeCl3                                                                             CuSO4                                                                             Fe(SO4)3                                                                          ZnSO4                                                                             NiCl2                              Modifier                                                                      pH, Modifier Solution                                                                      --  1   1     1   3.5 1   4.5 5.1                                Tap Water Wash                                                                pH           --  8   8     8    8  8   8    8                                 liters       --  not rec                                                                           app 6 app 30                                                                            0.3 3   1.2 1.0                                Deionized Water Wash, 1.                                                                   --  not rec                                                                           0     0   1.3 2   1.0 5.0                                pH of Final Wash                                                                           --   4.5                                                                              3.7    6.6                                                                              6.1  4.3                                                                              6.4 6.4                                Deetherification                                                              Conversion of                                                                              53* 85  88    14  88  94  49  14                                 IBTBE, mole %                                                                 Selectivity  97.5                                                                              98.1                                                                              97.3  99.3                                                                              97.0                                                                              95.5                                                                              99.0                                                                              98.8                               to Isobutene, mole %                                                          __________________________________________________________________________     *100° C. to avoid catalyst decomposition                               **Analysis of modified catalyst showed 6.18 wt % iron, chloride 70 ppm        ***Analysis of modified catalyst showed 5.83 wt % iron, chloride 80 ppm  

                  TABLE II                                                        ______________________________________                                        Arsenic           0.01     mg. per liter                                      Barium            0.50     "                                                  Chromium          0.02     "                                                  Copper            0.02     "                                                  Iron              0.02     "                                                  Lead              0.02     "                                                  Manganese         0.02     "                                                  Selenium          0.0002   "                                                  Silver            0.01     "                                                  Zinc              0.02     "                                                                  PORTABLE WATER                                                                ANALYSIS                                                      Calcium            5       mg. per liter                                      Magnesium         1        "                                                  Sodium            230      "                                                  Carbonate         11       "                                                  Bicarbonate       432      "                                                  Sulfate           3        "                                                  Chloride          83       "                                                  Flouride          2.3      "                                                  Nitrate as in     0.01     "                                                  CaCO3                                                                         Dissolved Solids  547      "                                                  Alkalinity as in  003      "                                                  CaCO3                                                                         pH                8.7      "                                                  ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        Hours on Stream                                                                             1       1.8      2.4   2.9                                      Reactor Temp. 290*    338**    338   338                                      (Steam Temp °F.)                                                       LHSV          6       6        2.5   2.5                                      Reaction Pressure, psig                                                                     160     200      200   200                                      Product Analysis                                                              Wt. %                                                                         Methanol      98.7    94.7     81.5  79.7                                     DME           1.3     5.3      18.5  20.3                                     Water         Not seen by GC                                                  ______________________________________                                         *Stem at 43 pounds pressure                                                   **Steam at 100 pounds pressure                                           

The invention claimed is:
 1. A process for the deetherification ofethers comprising of contacting said ether in vapor phase with a solidcatalyst composition comprising a resin of a macroporous matrix ofpolyvinyl aromatic compound crosslinked with a divinyl compound andhaving thereon from about 3 to 5 milli equivalents of sulfonic acidgroups per gram of dry resin, wherein at least 50% to less than 100% ofsaid sulfonic acid groups are neutralized with a metal of Al, Fe, Zn,Cu, Ni or mixtures thereof and said sulfonic acid groups not neutralizedwith said metal ion are neutralized with alkali metal ions or alkalineearth metal ions of Group 1a or 2a of the Periodic Table of elements ormixtures thereof.
 2. The process according to claim 1 wherein saidalkali metal ions or alkali earth metal ions are Li, Na, K, Mg, Ca, Sr,Ba or mixtures thereof.
 3. The process according to claim 2 wherein saidalkali metal ions or alkaline earth metal ions are Na, K, Mg, Ca ormixtures thereof.
 4. The process according to claim 1 wherein saidmacroporous matrix is polyvinyl styrene crosslinked with divinylbenzene.
 5. The process according to claim 4 wherein said metal ion isAl.
 6. The process according to claim 4 wherein said metal ion is Fe. 7.The process according to claim 4 wherein said metal ion is Zn.
 8. Theprocess according to claim 4 wherein the metal ion is Cu.
 9. The processaccording to claim 4 wherein the metal ion is Ni.
 10. The processaccording to claim 1 wherein at least 59% of said sulfonic acid groupsare neutralized with said metal ions.
 11. The process according to claim1 wherein from 70 to 90% of said sulfonic acid groups are neutralizedwith said metal ions.
 12. The process composition according to claim 1wherein the metal is a mixture of two or more of Al, Fe, Zn, Cu or Ni.13. The process according to claim 1 wherein the ether is methyltertiary butyl ether.
 14. The process according to claim 1 wherein theether is isobutyl tertiary butyl ether.
 15. The process according toclaim 1 wherein the temperature of said contacting is at a temperatureup to about 200° C.
 16. The process according to claim 15 wherein thetemperature is up to 170° C.
 17. The process according to claim 1wherein the ether is a C₁ to C₆ alkyl tertiary butyl ether.
 18. Theprocess according to claim 1 wherein the ether is a C₁ to C₆ alkyltertiary amyl ether.